<?php
/*
 *  $Id: Export.php 7490 2010-03-29 19:53:27Z jwage $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

/**
 * Doctrine_Export
 *
 * @package     Doctrine
 * @subpackage  Export
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 * @author      Lukas Smith <smith@pooteeweet.org> (PEAR MDB2 library)
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        www.doctrine-project.org
 * @since       1.0
 * @version     $Revision: 7490 $
 */
class Doctrine_Export extends Doctrine_Connection_Module
{
	protected $valid_default_values = array(
        'text'      => '',
        'boolean'   => true,
        'integer'   => 0,
        'decimal'   => 0.0,
        'float'     => 0.0,
        'timestamp' => '1970-01-01 00:00:00',
        'time'      => '00:00:00',
        'date'      => '1970-01-01',
        'clob'      => '',
        'blob'      => '',
        'string'    => ''
        );

        /**
         * drop an existing database
         * (this method is implemented by the drivers)
         *
         * @param string $name name of the database that should be dropped
         * @return void
         */
        public function dropDatabase($database)
        {
        	foreach ((array) $this->dropDatabaseSql($database) as $query) {
        		$this->conn->execute($query);
        	}
        }

        /**
         * drop an existing database
         * (this method is implemented by the drivers)
         *
         * @param string $name name of the database that should be dropped
         * @return void
         */
        public function dropDatabaseSql($database)
        {
        	throw new Doctrine_Export_Exception('Drop database not supported by this driver.');
        }

        /**
         * dropTableSql
         * drop an existing table
         *
         * @param string $table           name of table that should be dropped from the database
         * @return string
         */
        public function dropTableSql($table)
        {
        	return 'DROP TABLE ' . $this->conn->quoteIdentifier($table);
        }

        /**
         * dropTable
         * drop an existing table
         *
         * @param string $table           name of table that should be dropped from the database
         * @return void
         */
        public function dropTable($table)
        {
        	$this->conn->execute($this->dropTableSql($table));
        }

        /**
         * drop existing index
         *
         * @param string    $table        name of table that should be used in method
         * @param string    $name         name of the index to be dropped
         * @return void
         */
        public function dropIndex($table, $name)
        {
        	return $this->conn->exec($this->dropIndexSql($table, $name));
        }

        /**
         * dropIndexSql
         *
         * @param string    $table        name of table that should be used in method
         * @param string    $name         name of the index to be dropped
         * @return string                 SQL that is used for dropping an index
         */
        public function dropIndexSql($table, $name)
        {
        	$name = $this->conn->quoteIdentifier($this->conn->formatter->getIndexName($name));

        	return 'DROP INDEX ' . $name;
        }

        /**
         * drop existing constraint
         *
         * @param string    $table        name of table that should be used in method
         * @param string    $name         name of the constraint to be dropped
         * @param string    $primary      hint if the constraint is primary
         * @return void
         */
        public function dropConstraint($table, $name, $primary = false)
        {
        	$table = $this->conn->quoteIdentifier($table);
        	$name  = $this->conn->quoteIdentifier($name);

        	return $this->conn->exec('ALTER TABLE ' . $table . ' DROP CONSTRAINT ' . $name);
        }

        /**
         * drop existing foreign key
         *
         * @param string    $table        name of table that should be used in method
         * @param string    $name         name of the foreign key to be dropped
         * @return void
         */
        public function dropForeignKey($table, $name)
        {
        	return $this->dropConstraint($table, $name);
        }

        /**
         * dropSequenceSql
         * drop existing sequence
         * (this method is implemented by the drivers)
         *
         * @throws Doctrine_Connection_Exception     if something fails at database level
         * @param string $sequenceName      name of the sequence to be dropped
         * @return void
         */
        public function dropSequence($sequenceName)
        {
        	$this->conn->exec($this->dropSequenceSql($sequenceName));
        }

        /**
         * dropSequenceSql
         * drop existing sequence
         *
         * @throws Doctrine_Connection_Exception     if something fails at database level
         * @param string $sequenceName name of the sequence to be dropped
         * @return void
         */
        public function dropSequenceSql($sequenceName)
        {
        	throw new Doctrine_Export_Exception('Drop sequence not supported by this driver.');
        }

        /**
         * create a new database
         * (this method is implemented by the drivers)
         *
         * @param string $name name of the database that should be created
         * @return void
         */
        public function createDatabase($database)
        {
        	$this->conn->execute($this->createDatabaseSql($database));
        }

        /**
         * create a new database
         * (this method is implemented by the drivers)
         *
         * @param string $name name of the database that should be created
         * @return string
         */
        public function createDatabaseSql($database)
        {
        	throw new Doctrine_Export_Exception('Create database not supported by this driver.');
        }

        /**
         * create a new table
         *
         * @param string $name   Name of the database that should be created
         * @param array $fields  Associative array that contains the definition of each field of the new table
         *                       The indexes of the array entries are the names of the fields of the table an
         *                       the array entry values are associative arrays like those that are meant to be
         *                       passed with the field definitions to get[Type]Declaration() functions.
         *                          array(
         *                              'id' => array(
         *                                  'type' => 'integer',
         *                                  'unsigned' => 1
         *                                  'notnull' => 1
         *                                  'default' => 0
         *                              ),
         *                              'name' => array(
         *                                  'type' => 'text',
         *                                  'length' => 12
         *                              ),
         *                              'password' => array(
         *                                  'type' => 'text',
         *                                  'length' => 12
         *                              )
         *                          );
         * @param array $options  An associative array of table options:
         *
         * @return string
         */
        public function createTableSql($name, array $fields, array $options = array())
        {
        	if ( ! $name) {
        		throw new Doctrine_Export_Exception('no valid table name specified');
        	}

        	if (empty($fields)) {
        		throw new Doctrine_Export_Exception('no fields specified for table ' . $name);
        	}

        	$queryFields = $this->getFieldDeclarationList($fields);


        	if (isset($options['primary']) && ! empty($options['primary'])) {
        		$primaryKeys = array_map(array($this->conn, 'quoteIdentifier'), array_values($options['primary']));
        		$queryFields .= ', PRIMARY KEY(' . implode(', ', $primaryKeys) . ')';
        	}

        	if (isset($options['indexes']) && ! empty($options['indexes'])) {
        		foreach($options['indexes'] as $index => $definition) {
        			$indexDeclaration = $this->getIndexDeclaration($index, $definition);
        			// append only created index declarations
        			if ( ! is_null($indexDeclaration)) {
        				$queryFields .= ', '.$indexDeclaration;
        			}
        		}
        	}

        	$query = 'CREATE TABLE ' . $this->conn->quoteIdentifier($name, true) . ' (' . $queryFields;

        	$check = $this->getCheckDeclaration($fields);

        	if ( ! empty($check)) {
        		$query .= ', ' . $check;
        	}

        	$query .= ')';

        	$sql[] = $query;

        	if (isset($options['foreignKeys'])) {

        		foreach ((array) $options['foreignKeys'] as $k => $definition) {
        			if (is_array($definition)) {
        				$sql[] = $this->createForeignKeySql($name, $definition);
        			}
        		}
        	}
        	return $sql;
        }

        /**
         * create a new table
         *
         * @param string $name   Name of the database that should be created
         * @param array $fields  Associative array that contains the definition of each field of the new table
         * @param array $options  An associative array of table options:
         * @see Doctrine_Export::createTableSql()
         *
         * @return void
         */
        public function createTable($name, array $fields, array $options = array())
        {
        	// Build array of the primary keys if any of the individual field definitions
        	// specify primary => true
        	$count = 0;
        	foreach ($fields as $fieldName => $field) {
        		if (isset($field['primary']) && $field['primary']) {
        			if ($count == 0) {
        				$options['primary'] = array();
        			}
        			$count++;
        			$options['primary'][] = $fieldName;
        		}
        	}

        	$sql = (array) $this->createTableSql($name, $fields, $options);

        	foreach ($sql as $query) {
        		$this->conn->execute($query);
        	}
        }

        /**
         * create sequence
         *
         * @throws Doctrine_Connection_Exception     if something fails at database level
         * @param string    $seqName        name of the sequence to be created
         * @param string    $start          start value of the sequence; default is 1
         * @param array     $options  An associative array of table options:
         *                          array(
         *                              'comment' => 'Foo',
         *                              'charset' => 'utf8',
         *                              'collate' => 'utf8_unicode_ci',
         *                          );
         * @return void
         */
        public function createSequence($seqName, $start = 1, array $options = array())
        {
        	return $this->conn->execute($this->createSequenceSql($seqName, $start = 1, $options));
        }

        /**
         * return RDBMS specific create sequence statement
         * (this method is implemented by the drivers)
         *
         * @throws Doctrine_Connection_Exception     if something fails at database level
         * @param string    $seqName        name of the sequence to be created
         * @param string    $start          start value of the sequence; default is 1
         * @param array     $options  An associative array of table options:
         *                          array(
         *                              'comment' => 'Foo',
         *                              'charset' => 'utf8',
         *                              'collate' => 'utf8_unicode_ci',
         *                          );
         * @return string
         */
        public function createSequenceSql($seqName, $start = 1, array $options = array())
        {
        	throw new Doctrine_Export_Exception('Create sequence not supported by this driver.');
        }

        /**
         * create a constraint on a table
         *
         * @param string    $table         name of the table on which the constraint is to be created
         * @param string    $name          name of the constraint to be created
         * @param array     $definition    associative array that defines properties of the constraint to be created.
         *                                 Currently, only one property named FIELDS is supported. This property
         *                                 is also an associative with the names of the constraint fields as array
         *                                 constraints. Each entry of this array is set to another type of associative
         *                                 array that specifies properties of the constraint that are specific to
         *                                 each field.
         *
         *                                 Example
         *                                    array(
         *                                        'fields' => array(
         *                                            'user_name' => array(),
         *                                            'last_login' => array()
         *                                        )
         *                                    )
         * @return void
         */
        public function createConstraint($table, $name, $definition)
        {
        	$sql = $this->createConstraintSql($table, $name, $definition);

        	return $this->conn->exec($sql);
        }

        /**
         * create a constraint on a table
         *
         * @param string    $table         name of the table on which the constraint is to be created
         * @param string    $name          name of the constraint to be created
         * @param array     $definition    associative array that defines properties of the constraint to be created.
         *                                 Currently, only one property named FIELDS is supported. This property
         *                                 is also an associative with the names of the constraint fields as array
         *                                 constraints. Each entry of this array is set to another type of associative
         *                                 array that specifies properties of the constraint that are specific to
         *                                 each field.
         *
         *                                 Example
         *                                    array(
         *                                        'fields' => array(
         *                                            'user_name' => array(),
         *                                            'last_login' => array()
         *                                        )
         *                                    )
         * @return void
         */
        public function createConstraintSql($table, $name, $definition)
        {
        	$table = $this->conn->quoteIdentifier($table);
        	$name  = $this->conn->quoteIdentifier($this->conn->formatter->getIndexName($name));
        	$query = 'ALTER TABLE ' . $table . ' ADD CONSTRAINT ' . $name;

        	if (isset($definition['primary']) && $definition['primary']) {
        		$query .= ' PRIMARY KEY';
        	} elseif (isset($definition['unique']) && $definition['unique']) {
        		$query .= ' UNIQUE';
        	}

        	$fields = array();
        	foreach (array_keys($definition['fields']) as $field) {
        		$fields[] = $this->conn->quoteIdentifier($field, true);
        	}
        	$query .= ' ('. implode(', ', $fields) . ')';

        	return $query;
        }

        /**
         * Get the stucture of a field into an array
         *
         * @param string    $table         name of the table on which the index is to be created
         * @param string    $name          name of the index to be created
         * @param array     $definition    associative array that defines properties of the index to be created.
         *                                 Currently, only one property named FIELDS is supported. This property
         *                                 is also an associative with the names of the index fields as array
         *                                 indexes. Each entry of this array is set to another type of associative
         *                                 array that specifies properties of the index that are specific to
         *                                 each field.
         *
         *                                 Currently, only the sorting property is supported. It should be used
         *                                 to define the sorting direction of the index. It may be set to either
         *                                 ascending or descending.
         *
         *                                 Not all DBMS support index sorting direction configuration. The DBMS
         *                                 drivers of those that do not support it ignore this property. Use the
         *                                 function supports() to determine whether the DBMS driver can manage indexes.
         *
         *                                 Example
         *                                    array(
         *                                        'fields' => array(
         *                                            'user_name' => array(
         *                                                'sorting' => 'ascending'
         *                                            ),
         *                                            'last_login' => array()
         *                                        )
         *                                    )
         * @return void
         */
        public function createIndex($table, $name, array $definition)
        {
        	return $this->conn->execute($this->createIndexSql($table, $name, $definition));
        }

        /**
         * Get the stucture of a field into an array
         *
         * @param string    $table         name of the table on which the index is to be created
         * @param string    $name          name of the index to be created
         * @param array     $definition    associative array that defines properties of the index to be created.
         * @see Doctrine_Export::createIndex()
         * @return string
         */
        public function createIndexSql($table, $name, array $definition)
        {
        	$table  = $this->conn->quoteIdentifier($table);
        	$name   = $this->conn->quoteIdentifier($name);
        	$type   = '';

        	if (isset($definition['type'])) {
        		switch (strtolower($definition['type'])) {
        			case 'unique':
        				$type = strtoupper($definition['type']) . ' ';
        				break;
        			default:
        				throw new Doctrine_Export_Exception(
                        'Unknown type ' . $definition['type'] . ' for index ' . $name . ' in table ' . $table
        				);
        		}
        	}

        	$query = 'CREATE ' . $type . 'INDEX ' . $name . ' ON ' . $table;

        	$fields = array();
        	foreach ($definition['fields'] as $field) {
        		$fields[] = $this->conn->quoteIdentifier($field);
        	}
        	$query .= ' (' . implode(', ', $fields) . ')';

        	return $query;
        }
        /**
         * createForeignKeySql
         *
         * @param string    $table         name of the table on which the foreign key is to be created
         * @param array     $definition    associative array that defines properties of the foreign key to be created.
         * @return string
         */
        public function createForeignKeySql($table, array $definition)
        {
        	$table = $this->conn->quoteIdentifier($table);
        	$query = 'ALTER TABLE ' . $table . ' ADD ' . $this->getForeignKeyDeclaration($definition);

        	return $query;
        }

        /**
         * createForeignKey
         *
         * @param string    $table         name of the table on which the foreign key is to be created
         * @param array     $definition    associative array that defines properties of the foreign key to be created.
         * @return string
         */
        public function createForeignKey($table, array $definition)
        {
        	$sql = $this->createForeignKeySql($table, $definition);

        	return $this->conn->execute($sql);
        }

        /**
         * alter an existing table
         * (this method is implemented by the drivers)
         *
         * @param string $name         name of the table that is intended to be changed.
         * @param array $changes     associative array that contains the details of each type
         *                             of change that is intended to be performed. The types of
         *                             changes that are currently supported are defined as follows:
         *
         *                             name
         *
         *                                New name for the table.
         *
         *                            add
         *
         *                                Associative array with the names of fields to be added as
         *                                 indexes of the array. The value of each entry of the array
         *                                 should be set to another associative array with the properties
         *                                 of the fields to be added. The properties of the fields should
         *                                 be the same as defined by the MDB2 parser.
         *
         *
         *                            remove
         *
         *                                Associative array with the names of fields to be removed as indexes
         *                                 of the array. Currently the values assigned to each entry are ignored.
         *                                 An empty array should be used for future compatibility.
         *
         *                            rename
         *
         *                                Associative array with the names of fields to be renamed as indexes
         *                                 of the array. The value of each entry of the array should be set to
         *                                 another associative array with the entry named name with the new
         *                                 field name and the entry named Declaration that is expected to contain
         *                                 the portion of the field declaration already in DBMS specific SQL code
         *                                 as it is used in the CREATE TABLE statement.
         *
         *                            change
         *
         *                                Associative array with the names of the fields to be changed as indexes
         *                                 of the array. Keep in mind that if it is intended to change either the
         *                                 name of a field and any other properties, the change array entries
         *                                 should have the new names of the fields as array indexes.
         *
         *                                The value of each entry of the array should be set to another associative
         *                                 array with the properties of the fields to that are meant to be changed as
         *                                 array entries. These entries should be assigned to the new values of the
         *                                 respective properties. The properties of the fields should be the same
         *                                 as defined by the MDB2 parser.
         *
         *                            Example
         *                                array(
         *                                    'name' => 'userlist',
         *                                    'add' => array(
         *                                        'quota' => array(
         *                                            'type' => 'integer',
         *                                            'unsigned' => 1
         *                                        )
         *                                    ),
         *                                    'remove' => array(
         *                                        'file_limit' => array(),
         *                                        'time_limit' => array()
         *                                    ),
         *                                    'change' => array(
         *                                        'name' => array(
         *                                            'length' => '20',
         *                                            'definition' => array(
         *                                                'type' => 'text',
         *                                                'length' => 20,
         *                                            ),
         *                                        )
         *                                    ),
         *                                    'rename' => array(
         *                                        'sex' => array(
         *                                            'name' => 'gender',
         *                                            'definition' => array(
         *                                                'type' => 'text',
         *                                                'length' => 1,
         *                                                'default' => 'M',
         *                                            ),
         *                                        )
         *                                    )
         *                                )
         *
         * @param boolean $check     indicates whether the function should just check if the DBMS driver
         *                             can perform the requested table alterations if the value is true or
         *                             actually perform them otherwise.
         * @return void
         */
        public function alterTable($name, array $changes, $check = false)
        {
        	$sql = $this->alterTableSql($name, $changes, $check);

        	if (is_string($sql) && $sql) {
        		$this->conn->execute($sql);
        	}
        }

        /**
         * generates the sql for altering an existing table
         * (this method is implemented by the drivers)
         *
         * @param string $name          name of the table that is intended to be changed.
         * @param array $changes        associative array that contains the details of each type      *
         * @param boolean $check        indicates whether the function should just check if the DBMS driver
         *                              can perform the requested table alterations if the value is true or
         *                              actually perform them otherwise.
         * @see Doctrine_Export::alterTable()
         * @return string
         */
        public function alterTableSql($name, array $changes, $check = false)
        {
        	throw new Doctrine_Export_Exception('Alter table not supported by this driver.');
        }

        /**
         * Get declaration of a number of field in bulk
         *
         * @param array $fields  a multidimensional associative array.
         *      The first dimension determines the field name, while the second
         *      dimension is keyed with the name of the properties
         *      of the field being declared as array indexes. Currently, the types
         *      of supported field properties are as follows:
         *
         *      length
         *          Integer value that determines the maximum length of the text
         *          field. If this argument is missing the field should be
         *          declared to have the longest length allowed by the DBMS.
         *
         *      default
         *          Text value to be used as default for this field.
         *
         *      notnull
         *          Boolean flag that indicates whether this field is constrained
         *          to not be set to null.
         *      charset
         *          Text value with the default CHARACTER SET for this field.
         *      collation
         *          Text value with the default COLLATION for this field.
         *      unique
         *          unique constraint
         *
         * @return string
         */
        public function getFieldDeclarationList(array $fields)
        {
        	foreach ($fields as $fieldName => $field) {
        		$query = $this->getDeclaration($fieldName, $field);

        		$queryFields[] = $query;
        	}
        	return implode(', ', $queryFields);
        }

        /**
         * Obtain DBMS specific SQL code portion needed to declare a generic type
         * field to be used in statements like CREATE TABLE.
         *
         * @param string $name   name the field to be declared.
         * @param array  $field  associative array with the name of the properties
         *      of the field being declared as array indexes. Currently, the types
         *      of supported field properties are as follows:
         *
         *      length
         *          Integer value that determines the maximum length of the text
         *          field. If this argument is missing the field should be
         *          declared to have the longest length allowed by the DBMS.
         *
         *      default
         *          Text value to be used as default for this field.
         *
         *      notnull
         *          Boolean flag that indicates whether this field is constrained
         *          to not be set to null.
         *
         *      charset
         *          Text value with the default CHARACTER SET for this field.
         *
         *      collation
         *          Text value with the default COLLATION for this field.
         *
         *      unique
         *          unique constraint
         *
         *      check
         *          column check constraint
         *
         * @return string  DBMS specific SQL code portion that should be used to
         *      declare the specified field.
         */
        public function getDeclaration($name, array $field)
        {

        	$default   = $this->getDefaultFieldDeclaration($field);

        	$charset   = (isset($field['charset']) && $field['charset']) ?
                    ' ' . $this->getCharsetFieldDeclaration($field['charset']) : '';

        	$collation = (isset($field['collation']) && $field['collation']) ?
                    ' ' . $this->getCollationFieldDeclaration($field['collation']) : '';

        	$notnull   = $this->getNotNullFieldDeclaration($field);

        	$unique    = (isset($field['unique']) && $field['unique']) ?
                    ' ' . $this->getUniqueFieldDeclaration() : '';

        	$check     = (isset($field['check']) && $field['check']) ?
                    ' ' . $field['check'] : '';

        	$method = 'get' . $field['type'] . 'Declaration';

        	try {
        		if (method_exists($this->conn->dataDict, $method)) {
        			return $this->conn->dataDict->$method($name, $field);
        		} else {
        			$dec = $this->conn->dataDict->getNativeDeclaration($field);
        		}

        		return $this->conn->quoteIdentifier($name, true)
        		. ' ' . $dec . $charset . $default . $notnull . $unique . $check . $collation;
        	} catch (Exception $e) {
        		throw new Doctrine_Exception('Around field ' . $name . ': ' . $e->getMessage());
        	}

        }

        /**
         * getDefaultDeclaration
         * Obtain DBMS specific SQL code portion needed to set a default value
         * declaration to be used in statements like CREATE TABLE.
         *
         * @param array $field      field definition array
         * @return string           DBMS specific SQL code portion needed to set a default value
         */
        public function getDefaultFieldDeclaration($field)
        {
        	$default = '';

        	if (array_key_exists('default', $field)) {
        		if ($field['default'] === '') {
        			$field['default'] = empty($field['notnull'])
        			? null : $this->valid_default_values[$field['type']];

        			if ($field['default'] === '' &&
        			($this->conn->getAttribute(Doctrine_Core::ATTR_PORTABILITY) & Doctrine_Core::PORTABILITY_EMPTY_TO_NULL)) {
        				$field['default'] = null;
        			}
        		}

        		if ($field['type'] === 'boolean') {
        			$field['default'] = $this->conn->convertBooleans($field['default']);
        		}
        		$default = ' DEFAULT ' . (is_null($field['default'])
        		? 'NULL'
        		: $this->conn->quote($field['default'], $field['type']));
        	}

        	return $default;
        }


        /**
         * getNotNullFieldDeclaration
         * Obtain DBMS specific SQL code portion needed to set a NOT NULL
         * declaration to be used in statements like CREATE TABLE.
         *
         * @param array $field      field definition array
         * @return string           DBMS specific SQL code portion needed to set a default value
         */
        public function getNotNullFieldDeclaration(array $definition)
        {
        	return (isset($definition['notnull']) && $definition['notnull']) ? ' NOT NULL' : '';
        }


        /**
         * Obtain DBMS specific SQL code portion needed to set a CHECK constraint
         * declaration to be used in statements like CREATE TABLE.
         *
         * @param array $definition     check definition
         * @return string               DBMS specific SQL code portion needed to set a CHECK constraint
         */
        public function getCheckDeclaration(array $definition)
        {
        	$constraints = array();
        	foreach ($definition as $field => $def) {
        		if (is_string($def)) {
        			$constraints[] = 'CHECK (' . $def . ')';
        		} else {
        			if (isset($def['min'])) {
        				$constraints[] = 'CHECK (' . $field . ' >= ' . $def['min'] . ')';
        			}

        			if (isset($def['max'])) {
        				$constraints[] = 'CHECK (' . $field . ' <= ' . $def['max'] . ')';
        			}
        		}
        	}

        	return implode(', ', $constraints);
        }

        /**
         * Obtain DBMS specific SQL code portion needed to set an index
         * declaration to be used in statements like CREATE TABLE.
         *
         * @param string $name          name of the index
         * @param array $definition     index definition
         * @return string               DBMS specific SQL code portion needed to set an index
         */
        public function getIndexDeclaration($name, array $definition)
        {
        	$name   = $this->conn->quoteIdentifier($name);
        	$type   = '';

        	if (isset($definition['type'])) {
        		if (strtolower($definition['type']) == 'unique') {
        			$type = strtoupper($definition['type']) . ' ';
        		} else {
        			throw new Doctrine_Export_Exception(
                    'Unknown type ' . $definition['type'] . ' for index ' . $name
        			);
        		}
        	}

        	if ( ! isset($definition['fields']) || ! is_array($definition['fields'])) {
        		throw new Doctrine_Export_Exception('No columns given for index ' . $name);
        	}

        	$query = $type . 'INDEX ' . $name;

        	$query .= ' (' . $this->getIndexFieldDeclarationList($definition['fields']) . ')';

        	return $query;
        }

        /**
         * getIndexFieldDeclarationList
         * Obtain DBMS specific SQL code portion needed to set an index
         * declaration to be used in statements like CREATE TABLE.
         *
         * @return string
         */
        public function getIndexFieldDeclarationList(array $fields)
        {
        	$ret = array();
        	foreach ($fields as $field => $definition) {
        		if (is_array($definition)) {
        			$ret[] = $this->conn->quoteIdentifier($field);
        		} else {
        			$ret[] = $this->conn->quoteIdentifier($definition);
        		}
        	}
        	return implode(', ', $ret);
        }

        /**
         * A method to return the required SQL string that fits between CREATE ... TABLE
         * to create the table as a temporary table.
         *
         * Should be overridden in driver classes to return the correct string for the
         * specific database type.
         *
         * The default is to return the string "TEMPORARY" - this will result in a
         * SQL error for any database that does not support temporary tables, or that
         * requires a different SQL command from "CREATE TEMPORARY TABLE".
         *
         * @return string The string required to be placed between "CREATE" and "TABLE"
         *                to generate a temporary table, if possible.
         */
        public function getTemporaryTableQuery()
        {
        	return 'TEMPORARY';
        }

        /**
         * getForeignKeyDeclaration
         * Obtain DBMS specific SQL code portion needed to set the FOREIGN KEY constraint
         * of a field declaration to be used in statements like CREATE TABLE.
         *
         * @param array $definition         an associative array with the following structure:
         *          name                    optional constraint name
         *
         *          local                   the local field(s)
         *
         *          foreign                 the foreign reference field(s)
         *
         *          foreignTable            the name of the foreign table
         *
         *          onDelete                referential delete action
         *
         *          onUpdate                referential update action
         *
         *          deferred                deferred constraint checking
         *
         * The onDelete and onUpdate keys accept the following values:
         *
         * CASCADE: Delete or update the row from the parent table and automatically delete or
         *          update the matching rows in the child table. Both ON DELETE CASCADE and ON UPDATE CASCADE are supported.
         *          Between two tables, you should not define several ON UPDATE CASCADE clauses that act on the same column
         *          in the parent table or in the child table.
         *
         * SET NULL: Delete or update the row from the parent table and set the foreign key column or columns in the
         *          child table to NULL. This is valid only if the foreign key columns do not have the NOT NULL qualifier
         *          specified. Both ON DELETE SET NULL and ON UPDATE SET NULL clauses are supported.
         *
         * NO ACTION: In standard SQL, NO ACTION means no action in the sense that an attempt to delete or update a primary
         *           key value is not allowed to proceed if there is a related foreign key value in the referenced table.
         *
         * RESTRICT: Rejects the delete or update operation for the parent table. NO ACTION and RESTRICT are the same as
         *           omitting the ON DELETE or ON UPDATE clause.
         *
         * SET DEFAULT
         *
         * @return string  DBMS specific SQL code portion needed to set the FOREIGN KEY constraint
         *                 of a field declaration.
         */
        public function getForeignKeyDeclaration(array $definition)
        {
        	$sql  = $this->getForeignKeyBaseDeclaration($definition);
        	$sql .= $this->getAdvancedForeignKeyOptions($definition);

        	return $sql;
        }

        /**
         * getAdvancedForeignKeyOptions
         * Return the FOREIGN KEY query section dealing with non-standard options
         * as MATCH, INITIALLY DEFERRED, ON UPDATE, ...
         *
         * @param array $definition     foreign key definition
         * @return string
         */
        public function getAdvancedForeignKeyOptions(array $definition)
        {
        	$query = '';
        	if ( ! empty($definition['onUpdate'])) {
        		$query .= ' ON UPDATE ' . $this->getForeignKeyReferentialAction($definition['onUpdate']);
        	}
        	if ( ! empty($definition['onDelete'])) {
        		$query .= ' ON DELETE ' . $this->getForeignKeyReferentialAction($definition['onDelete']);
        	}
        	return $query;
        }

        /**
         * getForeignKeyReferentialAction
         *
         * returns given referential action in uppercase if valid, otherwise throws
         * an exception
         *
         * @throws Doctrine_Exception_Exception     if unknown referential action given
         * @param string $action    foreign key referential action
         * @param string            foreign key referential action in uppercase
         */
        public function getForeignKeyReferentialAction($action)
        {
        	$upper = strtoupper($action);
        	switch ($upper) {
        		case 'CASCADE':
        		case 'SET NULL':
        		case 'NO ACTION':
        		case 'RESTRICT':
        		case 'SET DEFAULT':
        			return $upper;
        			break;
        		default:
        			throw new Doctrine_Export_Exception('Unknown foreign key referential action \'' . $upper . '\' given.');
        	}
        }

        /**
         * getForeignKeyBaseDeclaration
         * Obtain DBMS specific SQL code portion needed to set the FOREIGN KEY constraint
         * of a field declaration to be used in statements like CREATE TABLE.
         *
         * @param array $definition
         * @return string
         */
        public function getForeignKeyBaseDeclaration(array $definition)
        {
        	$sql = '';
        	if (isset($definition['name'])) {
        		$sql .= 'CONSTRAINT ' . $this->conn->quoteIdentifier($this->conn->formatter->getForeignKeyName($definition['name'])) . ' ';
        	}
        	$sql .= 'FOREIGN KEY (';

        	if ( ! isset($definition['local'])) {
        		throw new Doctrine_Export_Exception('Local reference field missing from definition.');
        	}
        	if ( ! isset($definition['foreign'])) {
        		throw new Doctrine_Export_Exception('Foreign reference field missing from definition.');
        	}
        	if ( ! isset($definition['foreignTable'])) {
        		throw new Doctrine_Export_Exception('Foreign reference table missing from definition.');
        	}

        	if ( ! is_array($definition['local'])) {
        		$definition['local'] = array($definition['local']);
        	}
        	if ( ! is_array($definition['foreign'])) {
        		$definition['foreign'] = array($definition['foreign']);
        	}

        	$sql .= implode(', ', array_map(array($this->conn, 'quoteIdentifier'), $definition['local']))
        	. ') REFERENCES '
        	. $this->conn->quoteIdentifier($definition['foreignTable']) . '('
        	. implode(', ', array_map(array($this->conn, 'quoteIdentifier'), $definition['foreign'])) . ')';

        	return $sql;
        }

        /**
         * Obtain DBMS specific SQL code portion needed to set the UNIQUE constraint
         * of a field declaration to be used in statements like CREATE TABLE.
         *
         * @return string  DBMS specific SQL code portion needed to set the UNIQUE constraint
         *                 of a field declaration.
         */
        public function getUniqueFieldDeclaration()
        {
        	return 'UNIQUE';
        }

        /**
         * Obtain DBMS specific SQL code portion needed to set the CHARACTER SET
         * of a field declaration to be used in statements like CREATE TABLE.
         *
         * @param string $charset   name of the charset
         * @return string  DBMS specific SQL code portion needed to set the CHARACTER SET
         *                 of a field declaration.
         */
        public function getCharsetFieldDeclaration($charset)
        {
        	return '';
        }

        /**
         * Obtain DBMS specific SQL code portion needed to set the COLLATION
         * of a field declaration to be used in statements like CREATE TABLE.
         *
         * @param string $collation   name of the collation
         * @return string  DBMS specific SQL code portion needed to set the COLLATION
         *                 of a field declaration.
         */
        public function getCollationFieldDeclaration($collation)
        {
        	return '';
        }

        /**
         * exportSchema
         * method for exporting Doctrine_Record classes to a schema
         *
         * if the directory parameter is given this method first iterates
         * recursively trhough the given directory in order to find any model classes
         *
         * Then it iterates through all declared classes and creates tables for the ones
         * that extend Doctrine_Record and are not abstract classes
         *
         * @throws Doctrine_Connection_Exception    if some error other than Doctrine_Core::ERR_ALREADY_EXISTS
         *                                          occurred during the create table operation
         * @param string $directory     optional directory parameter
         * @return void
         */
        public function exportSchema($directory = null)
        {
        	if ($directory !== null) {
        		$models = Doctrine_Core::filterInvalidModels(Doctrine_Core::loadModels($directory));
        	} else {
        		$models = Doctrine_Core::getLoadedModels();
        	}

        	$this->exportClasses($models);
        }

        public function exportSortedClassesSql($classes, $groupByConnection = true)
        {
         $connections = array();
         foreach ($classes as $class) {
         	$connection = Doctrine_Manager::getInstance()->getConnectionForComponent($class);
         	$connectionName = $connection->getName();

         	if ( ! isset($connections[$connectionName])) {
         		$connections[$connectionName] = array(
                     'create_tables'    => array(),
                     'create_sequences' => array(),
                     'create_indexes'   => array(),
                     'alters'           => array(),
                     'create_triggers'  => array(),
         		);
         	}

         	$sql = $connection->export->exportClassesSql(array($class));

         	// Build array of all the creates
         	// We need these to happen first
         	foreach ($sql as $key => $query) {
         		// If create table statement
         		if (substr($query, 0, strlen('CREATE TABLE')) == 'CREATE TABLE') {
         			$connections[$connectionName]['create_tables'][] = $query;

         			unset($sql[$key]);
         			continue;
         		}

         		// If create sequence statement
         		if (substr($query, 0, strlen('CREATE SEQUENCE')) == 'CREATE SEQUENCE') {
         			$connections[$connectionName]['create_sequences'][] = $query;

         			unset($sql[$key]);
         			continue;
         		}

         		// If create index statement
         		if (preg_grep("/CREATE ([^ ]* )?INDEX/", array($query))) {
         			$connections[$connectionName]['create_indexes'][] =  $query;

         			unset($sql[$key]);
         			continue;
         		}

         		// If alter table statement or oracle anonymous block enclosing alter
         		if (substr($query, 0, strlen('ALTER TABLE')) == 'ALTER TABLE'
         		|| substr($query, 0, strlen('DECLARE')) == 'DECLARE') {
         			$connections[$connectionName]['alters'][] = $query;

         			unset($sql[$key]);
         			continue;
         		}

         		// If create trgger statement
         		if (substr($query, 0, strlen('CREATE TRIGGER')) == 'CREATE TRIGGER') {
         			$connections[$connectionName]['create_triggers'][] = $query;

         			unset($sql[$key]);
         			continue;
         		}

         		// If comment statement
         		if (substr($query, 0, strlen('COMMENT ON')) == 'COMMENT ON') {
         			$connections[$connectionName]['comments'][] = $query;

         			unset($sql[$key]);
         			continue;
         		}
         	}
         }

         // Loop over all the sql again to merge everything together so it is in the correct order
         $build = array();
         foreach ($connections as $connectionName => $sql) {
         	$build[$connectionName] = array_unique(array_merge($sql['create_tables'], $sql['create_sequences'], $sql['create_indexes'], $sql['alters'], $sql['create_triggers']));
         }

         if ( ! $groupByConnection) {
         	$new = array();
         	foreach($build as $connectionname => $sql) {
         		$new = array_unique(array_merge($new, $sql));
         	}
         	$build = $new;
         }
         return $build;
        }

        /**
         * exportClasses
         * method for exporting Doctrine_Record classes to a schema
         *
         * FIXME: This function has ugly hacks in it to make sure sql is inserted in the correct order.
         *
         * @throws Doctrine_Connection_Exception    if some error other than Doctrine_Core::ERR_ALREADY_EXISTS
         *                                          occurred during the create table operation
         * @param array $classes
         * @return void
         */
        public function exportClasses(array $classes)
        {
         $queries = $this->exportSortedClassesSql($classes);

         foreach ($queries as $connectionName => $sql) {
         	$connection = Doctrine_Manager::getInstance()->getConnection($connectionName);

         	$connection->beginTransaction();

         	foreach ($sql as $query) {
         		try {
         			$connection->exec($query);
         		} catch (Doctrine_Connection_Exception $e) {
         			// we only want to silence table already exists errors
         			if ($e->getPortableCode() !== Doctrine_Core::ERR_ALREADY_EXISTS) {
         				$connection->rollback();
         				throw new Doctrine_Export_Exception($e->getMessage() . '. Failing Query: ' . $query);
         			}
         		}
         	}

         	$connection->commit();
         }
        }

        /**
         * exportClassesSql
         * method for exporting Doctrine_Record classes to a schema
         *
         * @throws Doctrine_Connection_Exception    if some error other than Doctrine_Core::ERR_ALREADY_EXISTS
         *                                          occurred during the create table operation
         * @param array $classes
         * @return void
         */
        public function exportClassesSql(array $classes)
        {
        	$models = Doctrine_Core::filterInvalidModels($classes);

        	$sql = array();

        	foreach ($models as $name) {
        		$record = new $name();
        		$table = $record->getTable();
        		$parents = $table->getOption('joinedParents');

        		foreach ($parents as $parent) {
        			$data  = $table->getConnection()->getTable($parent)->getExportableFormat();

        			$query = $this->conn->export->createTableSql($data['tableName'], $data['columns'], $data['options']);

        			$sql = array_merge($sql, (array) $query);
        		}

        		// Don't export the tables with attribute EXPORT_NONE'
        		if ($table->getAttribute(Doctrine_Core::ATTR_EXPORT) === Doctrine_Core::EXPORT_NONE) {
        			continue;
        		}

        		$data = $table->getExportableFormat();

        		$query = $this->conn->export->createTableSql($data['tableName'], $data['columns'], $data['options']);

        		if (is_array($query)) {
        			$sql = array_merge($sql, $query);
        		} else {
        			$sql[] = $query;
        		}

        		if ($table->getAttribute(Doctrine_Core::ATTR_EXPORT) & Doctrine_Core::EXPORT_PLUGINS) {
        			$sql = array_merge($sql, $this->exportGeneratorsSql($table));
        		}

        		// DC-474: Remove dummy $record from repository to not pollute it during export
        		$table->getRepository()->evict($record->getOid());
        		unset($record);
        	}

        	$sql = array_unique($sql);

        	rsort($sql);

        	return $sql;
        }

        /**
         * fetches all generators recursively for given table
         *
         * @param Doctrine_Table $table     table object to retrieve the generators from
         * @return array                    an array of Doctrine_Record_Generator objects
         */
        public function getAllGenerators(Doctrine_Table $table)
        {
        	$generators = array();

        	foreach ($table->getGenerators() as $name => $generator) {
        		if ($generator === null) {
        			continue;
        		}

        		$generators[] = $generator;

        		$generatorTable = $generator->getTable();

        		if ($generatorTable instanceof Doctrine_Table) {
        			$generators = array_merge($generators, $this->getAllGenerators($generatorTable));
        		}
        	}

        	return $generators;
        }

        /**
         * exportGeneratorsSql
         * exports plugin tables for given table
         *
         * @param Doctrine_Table $table     the table in which the generators belong to
         * @return array                    an array of sql strings
         */
        public function exportGeneratorsSql(Doctrine_Table $table)
        {
        	$sql = array();

        	foreach ($this->getAllGenerators($table) as $name => $generator) {
        		$table = $generator->getTable();

        		// Make sure plugin has a valid table
        		if ($table instanceof Doctrine_Table) {
        			$data = $table->getExportableFormat();

        			$query = $this->conn->export->createTableSql($data['tableName'], $data['columns'], $data['options']);

        			$sql = array_merge($sql, (array) $query);
        		}
        	}

        	return $sql;
        }

        /**
         * exportSql
         * returns the sql for exporting Doctrine_Record classes to a schema
         *
         * if the directory parameter is given this method first iterates
         * recursively trhough the given directory in order to find any model classes
         *
         * Then it iterates through all declared classes and creates tables for the ones
         * that extend Doctrine_Record and are not abstract classes
         *
         * @throws Doctrine_Connection_Exception    if some error other than Doctrine_Core::ERR_ALREADY_EXISTS
         *                                          occurred during the create table operation
         * @param string $directory     optional directory parameter
         * @return void
         */
        public function exportSql($directory = null)
        {
        	if ($directory !== null) {
        		$models = Doctrine_Core::filterInvalidModels(Doctrine_Core::loadModels($directory));
        	} else {
        		$models = Doctrine_Core::getLoadedModels();
        	}

        	return $this->exportSortedClassesSql($models, false);
        }

        /**
         * exportTable
         * exports given table into database based on column and option definitions
         *
         * @throws Doctrine_Connection_Exception    if some error other than Doctrine_Core::ERR_ALREADY_EXISTS
         *                                          occurred during the create table operation
         * @return boolean                          whether or not the export operation was successful
         *                                          false if table already existed in the database
         */
        public function exportTable(Doctrine_Table $table)
        {
        	try {
        		$data = $table->getExportableFormat();

        		$this->conn->export->createTable($data['tableName'], $data['columns'], $data['options']);
        	} catch(Doctrine_Connection_Exception $e) {
        		// we only want to silence table already exists errors
        		if ($e->getPortableCode() !== Doctrine_Core::ERR_ALREADY_EXISTS) {
        			throw $e;
        		}
        	}
        }
}